RU2389924C2 - Amplifier of control action - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: amplifier refers to actuating facilities of control systems designed for converting input signals of low power into mechanical force of high power and can be used at systems of automatic or manual control. Here is disclosed application of a friction variator including friction links with crossing rotation axes. Angle of friction links crossing can vary. Also one of the links has spherical working surface with centre in the rotating axes crossing point. The second link is made in form of a ferrule with rollers which are in friction contact with spherical surface; axes of rollers are in plane passing through centre of spherical surface and perpendicular to ferrule rotation axis. The friction variator is equipped with a power drive and facility for control of value of crossing angle of friction links rotation axes. The friction variator is included into differential kinematic circuit comprising also an output shaft as an amplifier of control action.

EFFECT: simplification of design and raised reliability of amplifier of control action.

5 cl, 8 dwg

Description

The invention relates to actuators of control systems, and in particular, control action generating complexes intended for converting an input electrical, pneumatic, hydraulic or mechanical signal of low power into a mechanical control action of high power, and can be used in automatic or manual control systems for vehicles or technological processes.

Known electromechanical control amplifier, described in the book under the editorship of VV Solodovnikova "Elements of automatic control systems", M., Mashgiz, 1959, part 1, p. 681 ... 697.

This device contains a motor generator, the generator of which has an independent excitation, an electric motor with a gearbox and an electromagnetic clutch. The input signal is the command current supplied to the excitation winding of the generator, the control action is the rotation of the shaft of the electromagnetic clutch. The output shaft is reversed by an electromagnetic clutch.

The disadvantage of this amplifier control action is the low speed, the dependence of the speed of the output link from the load, low power gain and low efficiency.

Known electro-pneumatic control amplifier according to patent RU No. 2070714, 6 F42B 15/00, 08/11/1994, containing a power cylinder with a rotary piston mounted on the output shaft, into the cavity of which compressed air is supplied from a low pressure source through an electrically controlled distributor of the type “nozzle damper ".

The disadvantage of this control amplifier is the low power of the output signal and the high air flow rate due to its significant leaks in the nozzle-damper distributor.

The aforementioned disadvantages are deprived of the known electrically controlled control amplifier with a flat distribution valve according to RU patent No. 2216654, 7 F15B 13/12, 13/04, 02/14/2002, which controls the supply of fluid from a high pressure source in the cavity of the power cylinder connected to the output shaft .

The disadvantage of this control amplifier is the complexity of manufacturing precision structural elements and the need for a source of high pressure medium.

The need for a source of high-pressure medium is absent in the adopted as a prototype electro-hydraulic control amplifier according to patent RU No. 2052673, 6 F15B 9/00, 07.26.82.

The control amplifier contains an adjustable axial piston hydraulic pump located in the housing with an electric drive, the control element of which is connected to a servo piston located in the cylinder having a command cavity, a two-stage electrically controlled distributor, a hydraulic motor having a piston located in the cylinder and connected by feedback to the distributor made in the form of a spool with a command belt and bushings with a partition on the outer surface, two rows of holes, one of which are connected the piston chamber of the hydraulic motor, and the other - with the outlet manifold and the central windows, separated by a single wall, forming a two-cavity body, one of which is connected to a pumping line, and the other - to command the servo piston cavity. The input signal is an electric signal supplied to an electrically controlled distributor, the control action is the movement of the hydraulic piston.

The disadvantages of the device are the complexity of the design and configuration, and lack of reliability due to the presence of a large number of technologically complex and sensitive to operating conditions of hydraulic elements.

The essence of the invention is to simplify the design and increase the reliability of the control amplifier by using as such a friction variator according to the USSR author's certificate No. 217163, F16H 15/30, 1968 or patent RU No. 2112169, 6 F16H 15/04, 15/26, 07.25.1996 equipped with a power drive and a gear ratio control device and included in the differential kinematic scheme having an output shaft.

The variators according to the mentioned documents contain friction links with intersecting axes of rotation, mounted with the possibility of changing the angle of their intersection, one of the links having a spherical working surface centered at the intersection of the axes of rotation, the second is made in the form of a cage with rollers that are in friction contact with spherical surface and whose axes are located in a plane passing through the center of the spherical surface and perpendicular to the axis of rotation of the cage, and the rollers are pressed against the spherical overhnosti pusher cooperating with rollers axles (variator Copyright certificate USSR №217163) or an additional link with the spherical working surface cooperating with the outer surfaces of the rollers (variator according to the patent RU №2112169).

The gear ratio (the ratio of the angular velocities of the links) of these variators is controlled by rotating the axis of rotation of one of the friction links around an axis perpendicular to the axes of rotation of the links and passing through the point of intersection.

The input signal in the inventive control amplifier can be an electric, pneumatic, hydraulic or mechanical signal supplied to the corresponding control device of the transmission ratio of the variator.

The output control action is the rotation of the output shaft.

The energy for receiving the output signal of high power comes from the power drive. An electric, hydraulic or pneumatic (gas) engine with an output element in the form of a rotating shaft can be used as a power drive. If there is a shaft in the control object that has a constant angular velocity and sufficient power, it can also be used as a power drive.

The feasibility of using the variators of the indicated type as an amplifier of the control action is determined by the fact that the power of their control action can exceed the input signal power by more than 1000 times, since to control their gear ratio by turning the axis of rotation of the friction link it is enough to overcome the rolling resistance of the rollers of one friction link the spherical surface of another.

The feasibility of including the variator in the differential kinematic scheme is determined by the possibility, at a constant angular speed of the power drive shaft, to obtain rotation at the output shaft with various angular speeds controlled in magnitude and direction (including zero).

In technically justified cases (for example, with a small required resource of the control amplifier), it is advisable to use a simpler variator according to the USSR author's certificate No. 217163 (with friction contact by a pressure device), in other cases it is advisable to use a variator according to RU patent No. 2112169 (with friction contact by an additional link with a spherical working surface).

To minimize distortion of the output signal caused by kinematic errors of some parts of the differential kinematic scheme, friction gears can be used as the latter.

To reduce the number of kinematic links and reduce the size and weight of the control amplifier, the differential kinematic scheme can be performed by placing the variator in a rotating housing kinematically connected with the power drive.

To simplify the control device and reduce the inertial loads on the structural elements, the differential kinematic scheme can be performed by placing the variator in a fixed housing and including a separate differential mechanism in the circuit.

To increase the gain of the control amplifier, the variator can be multistage.

To optimize the dependence of the gain of the control amplifier on the magnitude of the input signal, nonlinear elements can be introduced into the control device.

The inventive control amplifier with parameters close to the prototype: speed, gear ratio, power gain and weight and size, structurally and technologically simpler than the prototype (in fact, it is less complicated than just one of the elements of the latter - adjustable axial piston hydraulic pump), and due to the lack of sensitive to the operating conditions of hydraulic elements it is more reliable than the prototype.

Examples of control amplifier circuits are presented in the drawings.

Figure 1 shows an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to the USSR copyright certificate No. 217163, placed in a rotating case.

Figure 2 shows a section along aa of the amplifier control action shown in figure 1.

Figure 3 shows an electrically controlled control amplifier with an electric motor as a power drive and a two-stage variator according to the USSR copyright certificate No. 217163, placed in a rotating case.

Figure 4 shows a section along aa of the amplifier control action shown in figure 3.

Figure 5 shows an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to patent RU No. 2112169, placed in a rotating housing.

Figure 6 shows a section along aa of the control amplifier shown in figure 5.

7 shows an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to patent RU No. 2112169, placed in a fixed housing with a separate differential mechanism.

On Fig shows a section along aa of the amplifier control action shown in Fig.7.

Figures 1 and 2 show a diagram of an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to the USSR copyright certificate No. 217163, placed in a rotating case.

The control amplifier includes a housing 1 with a power electric motor 2 installed on it. A gear 3 is fixed to the housing 1, it is also equipped with bearings 4 on which a rotating housing 5 is mounted with a shaft 6 connected to the shaft of the power motor 2. In a rotating housing 5 on bearings 7, an intermediate shaft with gears 8 and 9 is installed, a rotary frame 11 is mounted on the bearings 10, and an output shaft 13 is mounted on the bearings 12. In addition, an axis 14 is fixed in the rotary housing 5, on which a friction link is mounted on bearings 15 but 16 with a spherical working surface, equipped with a gear 17 interacting with the gear 9 of the intermediate shaft, and a control rotary electromagnet 18 is placed, the shaft of which is connected through the lever 19 to the rotary frame 11. In the rotary frame 11 on the bearings 20 there is a friction link 21 made in in the form of a cage with rollers 22 located with the working surface of the link 16 in the frictional contact created by the pressure device made in the form of elastically deformed levers 23. The axis of the bearings 10 (axis of rotation of the rotary frame) filled perpendicular to the axis of rotation of the housing 5 and the friction links 16 and 21 and intersecting with them in the center of the spherical working surface of the link 16. Between the rotary frame 11 and the wall of the rotating housing 5 is installed a spring 24. The shaft of the friction link 21 is a hinge of equal angular speeds 25, allowing linear and angular displacement of the connected shafts (see, for example, the reference manual "Mechanisms", ed. S.N. Kozhevnikova, Moscow: Engineering, 1976, pp. 383 ... 385, Fig. 6.9), is connected with the output shaft 13.

The control amplifier operates as follows.

The rotation of the shaft of the motor 2 through the shaft 6 is transmitted to the rotating housing 5, which causes the gear 8 and the intermediate shaft to rotate, and the rotation of the intermediate shaft through the gears 9 and 17, the friction links 16 and 21 and the constant velocity joint 25 are transmitted to the output shaft 13.

In the absence of an input signal on the control electromagnet 18, there is no moment on its shaft, and the rotary frame 11 and the axis of rotation of the friction link 21 occupies a position in which the moment created by the force of the spring 24 is the sum of the moments created by the inertia of the elements mounted on the rotary frame 11.

The mentioned spring force is selected so that with the nominal angular speed of the electric motor 2 and the absence of an input signal on the control solenoid 18, the axis of rotation of the friction link 21 coincides with the axis of rotation of the housing 5.

The angular velocity (ω ₂ ) _{0 of the} output shaft 13, in the absence of an input signal is determined by the ratio:

(ω ₂ ) ₀ = ω ₁ (1-Z ₃ Z ₉ cosα / Z ₈ Z ₁₇ ), where

ω ₁ - the angular velocity of the shaft 6;

Z ₃ - the number of gear teeth 3;

Z ₈ is the number of gear teeth 8;

Z ₉ is the number of gear teeth 9;

Z ₁₇ - the number of gear teeth 17;

α is the angle between the rotation axes of the interacting friction links in the absence of an input signal.

If the number of gear teeth is selected with the condition

Z ₃ Z ₉ / Z ₈ Z ₁₇ = 1 / cosα,

then in the absence of an input signal takes place

(ω ₂ ) ₀ = 0,

and if available

ω ₂ = ω ₁ [1-cos (α + β) / cosα], where

ω ₂ - the angular velocity of the output shaft 13;

β is the angle between the position of the axis of rotation of the friction link mounted on the swing frame, in the presence of an input signal and its position in the absence of an input signal.

The gain of the control amplifier

K = dω ₂ / dI = K _E K _1B , where

dI - input signal on electromagnet 18;

K _E - transfer coefficient of the electromagnet 18;

K _1B - gear ratio of a single-stage variator,

K _1B = dω ₂ / dβ = ω ₁ sin (α + β) / cosα.

Figures 3 and 4 show a diagram of an electrically controlled control amplifier with an electric motor as a power drive and a two-stage variator according to the USSR copyright certificate No. 217163, placed in a rotating case.

The control amplifier includes a housing 1 with a power electric motor 2 installed on it. A gear 3 is fixed to the housing 1, it is also equipped with bearings 4 on which a rotating housing 5 is mounted with a shaft 6 connected to the shaft of the electric motor 2. In the rotating housing 5 on the bearings 26 two identical friction links 27 with spherical working surfaces are installed, equipped with gears 28 interacting with the fixed gear 3, a rotary frame 11 is mounted on the bearings 10, and a friction e link 21, link 21, similar to that shown in Figures 1 and 2, a shaft 13 which is an output. In addition, a control rotary electromagnet 18 is placed in the housing 5, the shaft of which is connected through the lever 19 to the rotary frame 11. An axis 14 and two axles 29 are fixed on the rotary frame 11. A friction link 16 with a spherical working surface is mounted on bearings 15 of the axis 14 gear 17. To reduce the total moment of inertia of the elements kinematically connected with the shaft of the control electromagnet 18, the friction link 16 is hollow. Two identical friction links 31 are mounted on bearings 30 of axles 29, similar to link 21, the rollers 32 of which are in frictional contact with the spherical working surfaces of the respective links 27. Friction links 31 are equipped with gears 33 interacting with gear 17. Bearing axis 10 (pivot axis of rotation frame) is made perpendicular to the axis of rotation of the housing 5 and all friction links (16, 21, 27 and 31) and intersecting with them at the centers of the spherical working surfaces of the links 16 and 27. In this case, the axis of rotation of the housing 5 and f the friction links 21 and 27, as well as the axis of rotation of the friction links 16 and 31, are made parallel to each other. Between the rotary frame 11 and the wall of the rotating housing 5, a spring 24 is installed.

The control amplifier operates as follows.

The rotation of the shaft of the electric motor 2 through the shaft 6 is transmitted to the rotating housing 5, which causes the friction links 27 to rotate, the gears 28 of which interact with the stationary gear 3. The rotation of the friction links 27 is transmitted to the friction links 31 interacting with them and is transmitted to the friction link 16 through the gears 33 and 17, and from it to the friction link 21 interacting with it and the output shaft 13.

In the absence of an input signal on the control solenoid 18, there is no moment on its shaft, and the rotary frame 11 and the axis of rotation of the friction links 16 and 31 occupy a position in which the moment created by the force of the spring 24 is equal to the sum of the moments created by the inertia of the elements mounted on the rotary frame eleven.

The angular velocity of the output shaft 13 in the absence of an input signal is determined by the ratio:

(ω ₂ ) ₀ = ω ₁ (1-Z ₃ Z ₃₃ cos ² α / Z ₂₈ Z ₁₇ ), where

Z ₂₈ - the number of gear teeth 28;

Z ₃₃ is the number of gear teeth 33.

If the number of gear teeth is selected subject to the conditions:

Z ₃ Z ₃₃ / Z ₂₈ Z ₁₇ = 1 / cos ² α,

then in the absence of an input signal takes place

(ω ₂ ) ₀ = 0,

and if available

ω ₂ = ω ₁ [1-cos ² (α + β) / cos ² α].

Gear ratio of a two-stage variator,

K _2B = dω ₂ / dβ = 2ω ₁ [sin (α + β) / cos ² α], or

K _2B = 2K _1B / cosα,

which shows that for the same values (see page 9) of _KE , α, β, and ω _1, the transmission coefficient of the control amplifier with a two-stage variator exceeds the transmission coefficient of the control amplifier with a single-stage variator more than twice.

To reduce differences in the transmission coefficients K _2B at angles β of different signs, the kinematic connection of the electromagnet 18 with the rotary frame is asymmetric.

Figures 5 and 6 show a diagram of an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to patent RU No. 2112169, placed in a rotating case.

The control amplifier includes a housing 1 with a power electric motor 2 installed on it. A gear 3 is fixed to the housing 1, it is also equipped with bearings 4, on which a rotating housing 5 is mounted with a shaft 6 connected to the shaft of the electric motor 2. In the rotating housing 5 on the bearings 7 an intermediate shaft with gears 8 and 9 is installed, a rotary frame 11 is mounted on bearings 10, an output shaft 13 is mounted on bearings 12, and a friction link 16 with an internal spherical working surface equipped with a gear is mounted on bearings 15 17, interacting with the gear 9 of the intermediate shaft. In addition, in the rotary housing 5 there is a control motor 18, the shaft of which is connected by a gear 34 and a gear sector 35 with a rotary frame 11. A friction link 21 is mounted on the rotary frame 11, made in the form of a cage with rollers 22 located with the working surface of the link 16 in the frictional contact created by the additional spherical link 36 interacting with the rollers 22 and the centering bearings 37. The bearings of the friction link 21 are the bearing 20 and the inner spherical working surface of the friction link 16. O Bearings 10 s (the swing frame pivot axis) is arranged perpendicular to the axis of rotation of the housing 5 and frictional units 16 and 21 and intersecting therewith at the center of the spherical work surface 16. The link between the pivoting frame 11 and the wall of the rotating body 5, spring 24 is installed.

The shaft of the friction link 21 by a joint of equal angular velocities 25, allowing linear and angular displacement of the connected shafts is connected with the output shaft 13.

The control amplifier operates identically to the device described above (p. 7 ... 8) with a variator according to the USSR copyright certificate No. 217163.

Figures 7 and 8 show a diagram of an electrically controlled control amplifier with an electric motor as a power drive and a single-stage variator according to patent RU No. 2112169, placed in a fixed housing together with a separate differential mechanism included in the kinematic circuit.

In the housing 1 of the control amplifier, there is a power motor 2 with gears 36 and 37 on its shaft and a control motor 18 with gear 34 on the shaft. On the bearings 15 of the housing 1, a friction link 16 with an internal spherical working surface is mounted, equipped with a gear 17 interacting with the gear 36, on the bearings 10 - a rotary frame 11 with the gear sector 35, interacting with the gear 34, on the bearings 38 - the shaft 39 of the differential mechanism, on bearings 40, a housing 41 of a differential mechanism with gear 42 with internal teeth and gear 43 interacting with gear 37. Friction link 21, made in the form of a cage with rollers 22, is mounted on the rotary frame 11 walking with the working surface of the link 16 in the frictional contact created by the additional spherical link 36, interacting with the rollers 22 and the centering bearings 37. The bearings of the friction link 21 are the bearing 20 and the inner spherical working surface of the friction link 16. In the housing of the differential mechanism 41 on the bearings 12 is installed an output shaft 13, in the inner cavity of which is on bearings 44, whose axis is parallel to the axis of the shaft 13 and offset relative to it, a satellite 45 is mounted kinematically connected to the shaft 39 with a crank gear 46 and interacting with the gear 43. The friction link 21 is the shaft 47 and two equal speed angular joints 48, made in the form of dual cardan joints, kinematically connected with the shaft 39 of the differential mechanism. The axis of the bearings 10 (the axis of rotation of the pivoting frame) is made perpendicular to the axis of rotation of the friction links 16 and 21 and intersects with them in the center of the spherical working surface of the link 16. The output shaft 13, the housing of the differential mechanism 41 and the shaft 39 are aligned and their axis of rotation passes through the center a spherical working surface of the friction link 16. Between the rotary frame 11 and the wall of the housing 1, a spring 24 is installed.

The control amplifier operates as follows.

The rotation of the shaft of the motor 2 through the gears 36 and 17 is transmitted to the friction link 16 and the friction link 21 interacting with it, and from it, through the shaft 47 with hinges of equal angular speeds 48, the rotation is transmitted to the shaft 39 of the differential mechanism and, through the connecting rod gear 46, to the satellite 45. At the same time, the rotation of the shaft of the electric motor 2 through the gears 37 and 43 is transmitted to the housing of the differential mechanism 41 with the gear 42 and is summed with the rotation of the satellite 45, which results in the rotation of the output shaft 13.

In the absence of an input signal on the control solenoid 18, there is no moment on its shaft, and the rotary frame 11 and the axis of rotation of the friction link 21 occupies a position in which the moment created by the force of the spring 24 is equal to the moment created by the inertia of the non-uniformly rotating rollers 22. The mentioned spring force is selected so that with the nominal angular speed of the electric motor 2 and the absence of an input signal on the control solenoid 18, the rotation axis of the friction link 21 coincides with the common rotation axis of the output shaft 13, differential gear housing 41 and shaft 39.

The angular velocity of the output shaft 13 in the absence of an input signal is determined by the ratio:

(ω ₂ ) ₀ = ω ₁ (Z ₃₆ Z ₄₅ cosα / Z ₁₇ Z ₄₂ -Z ₃₇ / Z ₄₃ ) / (1-Z ₄₅ / Z ₄₂ ), where

Z ₃₆ - the number of gear teeth 36,

Z ₃₇ - the number of gear teeth 37,

Z ₄₃ - the number of gear teeth 43,

Z ₄₅ - the number of teeth of the satellite 45,

Z ₄₂ is the number of gear teeth 42.

If the number of gear teeth is selected subject to the condition

Z ₃₆ Z ₄₅ cosα / Z ₁₇ Z ₄₂ = Z ₃₇ / Z ₄₃ ,

then in the absence of an input signal takes place

(ω ₂ ) ₀ = 0,

and if available

ω ₂ = - [Z ₃₇ / Z ₄₃ (1-Z ₄₅ / Z ₄₂ )] · _{1 1} [1-cos (α + β) / cosα]

and transmission coefficient of a single-stage variator with a separate differential mechanism,

K _1B = dω ₂ / dβ = - [Z ₃₇ / Z ₄₃ (1-Z ₄₅ / Z ₄₂ )] · ω ₁ sin (α + β) / cosα.

Claims (5)

1. The use of a friction variator containing friction links with intersecting axes of rotation, installed with the possibility of changing the angle of intersection, one of the links having a spherical working surface centered at the intersection of the axes of rotation, the second is made in the form of a cage with rollers that are in the friction contact with a spherical surface and whose axes are located in a plane passing through the center of the spherical surface and perpendicular to the axis of rotation of the holder, equipped with a power drive and a control device for the angle of intersection of the axes of rotation of the friction links and included in the differential kinematic scheme, which includes an output shaft, as an amplifier for the control action. 2. The use of the friction variator according to claim 1, characterized in that the differential kinematic scheme uses friction gears as an amplifier for the control action. 3. The use of the friction variator according to claim 1, characterized in that the differential kinematic circuit is arranged with the variator in a rotatable housing kinematically connected with a power drive as a control amplifier. 4. The use of the friction variator according to claim 1, characterized in that the differential kinematic circuit is made by placing the variator in a fixed housing and incorporating into the circuit a separate differential mechanism as an amplifier of the control action. 5. The use of the friction variator according to claim 1, characterized in that the variator is multi-stage, as a control amplifier.

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